Compressor buildings

Review the compressor building ventilation system to ensure that it has adequate capacity lo maintain acceptable temperatures in the co(n[>rcssor bays... 

Figure 15-24. Insulation is not necessary on the portion of the exhaust system extending outside the compressor building because it is not in a classified area and is not a work area. The inside portion needs insulation because it is in a classified areo.

Sensing heads should be located in draft-free areas where possible, as air flowing past the sensors normally increases drift of calibration, shortens head life, and decreases sensitivity. Air deflectors are available from sensor manufacturers and should be utilized in any areas where significant air flow is anticipated (such as air conditioner plenum applicaiion.s). Additionally, sensors should be located, whenever possible, in loca[ion.s which are relatively free from vibration and easily accessed for calibration and maintenance. Obviously, this carmot always be accomplished. It usually is difficult, for example, to locate sensors in the tops of compressor buildings at locations which are accessible and which do not vibrate. 

This case uses the large cloud, as in Cases 2 and 3, but the ignition point is moved to the center of the space under the compressor building (IGN3). 

Compressor buildings are often elevated to allow the necessary clearance for the installation of drums direcdy below the cylinders. Suction drums are usually located on top of the cylinders. Installation outside the compressor building is considered poor practice, except in special cases. 

The unmanned compressor building was equipped with a combustible gas detection system. However, it failed to sound an alarm because of a faulty relay in the control room. Automatic fail-safe valves functioned properly, blocking-in the flow of ethylene, but not before 450-11,000 lb of gas had already escaped. 

Gas compressor buildings that may be fully or partially enclosed. 

Location of Compressor Building. The main compressor building for hydrogen gas compressor stations shall be located at such clear distances from adjacent property not under control of the company as to minimize the hazard of communication of fire to the compressor building from structures on adjacent property. Sufficient open space should be provided around the building to permit the free movement of firefighting equipment. 

I-1.3.6.3 The compressor building configuration shall be considered in selecting the number, type, and placement of detectors and alarms. 

Where multiple compressors are involved in the same service or duty, separation should be provided between compressors to reduce mutual exposure. Compressor buildings housing flammable service compressors should be provided with a combustible-gas detection system. The system should alarm at a concentration of 20-25% of the LFL and shutdown the compressor at 40-50% LFL (see Section 8.1.3). The shutdown should include closing all inlet and discharge process lines. For reciprocating compressors in flammable service, explosion vents on the crankcases should be provided. 

Figure 7.1-8. Cross section of a polyethylene compressor building [16].

In one reported case, a construction manager reviewed the drawings of a gas compressor building before construction. He observed that very weak clips were specified to secure the plastic sheets to the structure. He apparently did not understand the concept, because he decided they were too weak and replaced the specified clips with more robust clips. 

Compressor build-up rate. When rebuilding the air pressure after checking the alarm and button pop out, the driver should note how long it takes the compressor to build the reservoir tanks from 85 to 100 psi. It should take no longer than 45 seconds at operating RPMs (normally 1500 to 1800 RPMs). 

Gauges indicating the pressure in the working chamber shall be installed in the compressor building, the lock attendant s station, and at the employer s field office. 

Consider use of open compressor buildings to avoid accumulation of released vapors. 

AU compressor engines and turbines should receive combustion air from outside the compressor building through filtered air intakes, which are located on the opposite side of the building from the process equipment. The air filters should preferably be located on the prevailing wind side of the building. 

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